deflectometer

A deflectometer is an instrument designed to measure the deflection of a body or surface under load, including linear displacement and angular tilt. It converts physical deflection into a readable signal for analysis.

Two common implementations are optical deflectometers, which track the deflection by measuring shifts of light (for example via a laser beam and position-sensitive detector or interferometric setup), and mechanical deflectometers, which use a calibrated probe, cantilever, or stylus whose deflection is transduced by capacitive, inductive, or optical sensors.

A typical deflectometer consists of a source of sensing energy, a transducer to convert displacement into an electrical signal, and a readout system. Outputs are usually displacement in meters or micrometers, or angle in radians or milliradians, with resolutions depending on the design. Dynamic measurements may require high-speed sensors and data processing.

Applications include structural testing, materials characterization, surface metrology, optical alignment, and vibration analysis. Deflectometry relies on careful calibration and environmental control; sources of error include temperature changes, mechanical backlash, and noise in the sensing channel.

The term deflectometer describes a family of devices rather than a single standard instrument, with various designs optimized for different ranges, resolutions, and measurement contexts. Related technologies include dial gauges, profilometers, laser interferometers, and accelerometers used for indirect deflection measurement.